title: Angiographic and clinical characteristics according to intracoronary acetylcholine dose in patients with myocardial bridge.
abstract: OBJECTIVE
  It is well known that myocardial bridge (MB) is a risk factor of vasospastic angina. However, clinical and angiographic characteristics according to different acetylcholine (ACh) dose in patients with MB are not clarified yet.
  
  
  METHODS
  A total 483 consecutive patients who had angiographically proven MB underwent the intracoronary ACh provocation test. ACh was injected by incremental doses of 20, 50 and 100 μg into the left coronary artery. We evaluated the clinical and angiographic characteristics of patients with MB according to 3 different ACh doses.
  
  
  RESULTS
  The baseline clinical and procedural characteristics are well balanced among the three groups. The MB patients who responded to the lower ACh dose (20 μg) had higher incidence of baseline spasm, severe vasospasm and diffuse long spasms (>30 mm) than those who responded to the higher doses (50 and 100 μg). The incidence of 12-month mortality and recurrent chest pain was higher in the lower ACh dose group (20 μg).
  
  
  CONCLUSIONS
  The patients with MB significantly reacting at the low ACh dose had more pronounced baseline spasm, severe and diffuse long coronary artery spasm, higher 12-month mortality and recurrent chest pain than those reacting with the higher ACh doses, suggesting that more intensive medical therapy will be required.
authors.affiliation: Cardiovascular Center, Korea University Guro Hospital, Seoul, Korea.
authors.forename: Sung Il
authors.initials: SI
authors.lastname: Im
authors.forename: Seung-Woon
authors.initials: SW
authors.lastname: Rha
authors.forename: Byoung Geol
authors.initials: BG
authors.lastname: Choi
authors.forename: Se Yeon
authors.initials: SY
authors.lastname: Choi
authors.forename: Sun Won
authors.initials: SW
authors.lastname: Kim
authors.forename: Jin Oh
authors.initials: JO
authors.lastname: Na
authors.forename: Cheol Ung
authors.initials: CU
authors.lastname: Choi
authors.forename: Hong Euy
authors.initials: HE
authors.lastname: Lim
authors.forename: Jin Won
authors.initials: JW
authors.lastname: Kim
authors.forename: Eung Ju
authors.initials: EJ
authors.lastname: Kim
authors.forename: Chang Gyu
authors.initials: CG
authors.lastname: Park
authors.forename: Hong Seog
authors.initials: HS
authors.lastname: Seo
authors.forename: Dong Joo
authors.initials: DJ
authors.lastname: Oh
mesh_terms: D000109:Acetylcholine / Q000008:administration & dosage; D000788:Angina Pectoris, Variant / Q000175:diagnosis* / Q000209:etiology; D017023:Coronary Angiography / Q000379:methods; D023921:Coronary Stenosis / Q000175:diagnosis; D003329:Coronary Vasospasm / Q000209:etiology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D054084:Myocardial Bridging / Q000150:complications* / Q000000981:diagnostic imaging; D014665:Vasodilator Agents / Q000008:administration & dosage
chemical_list: D014665:Vasodilator Agents; D000109:Acetylcholine